The present invention pertains generally to fiber optic communication devices and more particularly to modular transceiver units for use in a local area network hub.
With the increasing use of programmable data processing apparatus, local area networks for communicating between central processing units, terminals, peripherals, etc., have gained wide acceptance and increased use. Typical local area networks such as the ARCNET.RTM. (a registered trademark of the Data Point Corporation) local area network system employ co-axial cables as a communication link between spatially separated units in the system. Typical co-axial cable local area networks utilize active hubs which have a plurality of co-axial cable ports for connecting one or more devices which communicate within the local area network. Each of the co-axial ports is connected to an electronic modular package which processes the signal for communication with the local area network.
Fiber optic communication links provide a significant advantage over co-axial communication links because of the immunity of fiber optic links to electromagnetic interference and radio frequency interference, increased bandwidth over length, which increases data communication distance for the same speed, and increased security from unauthorized tapping of the network. Also, optical fibers will soon be lower in cost than wire. Consequently, it would be desirable to provide a pin compatible module for use in an active hub, wire concentrator, terminal device, and other devices, to replace co-axial cable communication ports with a fiber optic communication ports to provide the ability to communicate through one or more ports with fiber optic links. Such a system would, however, be limited by the space provided in an active hub, wire concentrator, terminal device, or other similar devices so that the number and size of components in such a compatible module would be limited. Additionally, because of established connector configurations of devices in which an electronic module could be used, problems of cross-talk and virtual capacitance at the high frequencies of operation of the system must necessarily be overcome because of the inability to change the pin configuration of the connector configuration which was designed for coaxial communications.